A mobile device has to be aware of whether a Subscriber Identification Module (SIM) card is in an inserted state or not (e.g., in relation to the mobile device), even after the mobile device is booted. In order to determine whether the SIM card is inserted in relation to the mobile device, 3GPP TS 31.101 prescribes that a mobile device should generate a polling signal at regular intervals to check the state of the SIM card.
Normally, in a sleep mode, a mobile device supplies no electric power or the minimum electric power to peripheral devices such as a display unit in order to reduce power consumption. In this state, a SIM card polling process requires a wake-up of both a baseband chip and a Power Management Unit (PMU). Requiring the baseband chip and the PMU to wake-up in order to perform the SIM card polling process causes unnecessary power consumption of about 100 mA for about one second. Therefore, a battery management technique to reduce such power consumption is needed.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.